Presettable automatic timing device



Jan. 12, 1960 F. e. KRAL PRESETTABLE AUTOMATIC TIMING DEVICE Filed Nov. 29, 1957 2 Sheets-Sheet l /NVENTOR- By ATTORNEYS.

Jan. 12, 1960 F. G. KRAL PRESETTABLE AUTOMATIC TIMING DEVICE Filed Nov. 29, 1951 2 Sheets-Sheet 2 WV N TOR I fl g 9 4 ATTORNEYS.

United States Patent M PRESETTABLE AUTOMATIC TIMING DEVICE Fred G. Kral, Hillside, Ill., assignor to Guardian Electric Manufacturing Company, a corporation of Illinois Application November 29, 1957, Serial No. 699,568

11 Claims. (Cl. 200-38) This application relates generally to switching and con- .trol apparatus, and more particularly to improvements in presettable switching and control apparatus of the type used in timing and sequencing systems and the like.

Many systems are known which require a timing function of the type wherein electrical control signals are supplied at desired times and in a desired sequence. Various timing devices have been utilized in the prior art for effecting this type of timing function, and commonly these devices take the form of switch actuating mechanisms which are operative to momentarily close one or more circuit energizing switches in a fixed or predetermined sequence.

It is a general object of this invention to provide a new and improved presettable control apparatus for effecting a sequential switching function.

It is another object of this invention to provide an im- 2,921,151 Patented Jan. 12, 1960 rotation by a suitable drive source, such as a constant speed electric motor.

In accordance with the features of one preferred construction, each of said presettable timing elements comprises an indexing or calibration wheel which has fixed around 180 of its outer periphery a graduated time scale corresponding to one half of the time period of proved automatic timing device which is operative to signals.

It is still another object of this invention to provide an improved automotic timing device for sequentially operating a plurality of circuit energizing switches which comprises an individually settable indexing wheel having cam means capable of actuating one or more of said circuit energizing switches to effect a desired switching function.

It is a further object of this invention to provide an improved automatic timing device, as described above, which comprises a plurality of individually settable indexing wheels having cam means adapted to be driven from a common drive source.

It is a still further object of this invention to provide an improved automatic timing device, as described above wherein the cam means of each indexing wheel actuates a circuit energizing switch at a presettable time in the cycle of operation of the driving mechanism and maint ains the switch actuated through the remainder of the cycle. a

It is still a further object of this invention to provide an improved automatic timing device which can be reset to the start position at the end of a cycle of operation with all of the preset time settings on the various in dexing wheels remaining in their original positions.

It is a still further object of this invention to provide an improved automatic timing device, as described above, which is characterized by its compact construction, its reliability and its resistance to high shock and vibration environments.

These and other objects are realized in accordance with a specific illustrative embodiment of this invention in. which one or more unique presettable timing elements is operatively associated with a common drive shaft for the drive motor output. Advantageously, the edge of the indexing wheel is knurled so that when the timing element is assembled in operative condition, the indexing wheel is turned by thumbing the knurled edge to the desired time setting in the driving cycle in which the switch associated with the timing element is to be actuated and remain actuated for the remainder of the driving cycle.

This operation is effected by means of a cam wheel associated with the indexing wheel by means of a telescoping bushing arrangement, i.e., a female bushing is staked. to the central aperture of the indexing wheel and a male bushing is staked to the central aperature of the cam wheel. Thus the indexing and cam wheels are axially movable relative to each other and suitable spring means are provided between the wheels to the end that the cam wheel is spring loaded away from the indexing wheel on the drive shaft.

The bushing of the indexing wheel is secured to a suitable support bracket such that the indexing wheel is free to rotate in the bushing around the axis of the drive shaft when its knurled edge is manually operated. The indexing wheel is coupled to the cam wheel, as for example, by means of -a stud secured to one wheel and protruding into a bushing in the other wheel, and consequently, as the indexing wheel is rotated to a desired setting, the cam wheel is rotated in a corresponding manner. This assembly permits relative motion between the index wheel and the cam wheel in an axial direction, but when the index wheel is rotated around the drive shaft, the cam wheel will follow.

A rotor assembly comprising a pair of oppositely disposed arms of different lengths is positioned on the drive shaft and a roller at the end of each arm rides in a raceway cut into the face of the cam wheel. The rotor is secured to the drive shaft, and in the operation of the invention the rotor revolves with the drive shaft when the motor is energized. Each raceway tapers up to the cam wheel face at the ends of its 180 arc, and :as the rotor is rotated by the drive shaft, the rollers at the ends of the rotor arms move the cam wheel towards the indexing wheel at the preset point in the cycle.

In accordance with a further feature of this invention, the armature of at least one circuit energizing switch is in operative contact with a surface of the cam wheel, such that when the rotor rollers ride in the raceways and the cam wheel is spring-biased away from the index wheel, the switch armature is maintained at one of its operating positions. When the drive shaft rotates the rotor rollers out of the raceway at the preset time in the cycle, the rollers ride up the tapered portions of the raceways and force the cam wheel to move axially towards the index wheel, and this transversion actuates the switch armature to its other operating position.

Further features of this invention include a locking mechanism for each index wheel to prevent its rotation except when a new setting is desired, a magnetic clutch responsive to a limit switch for releasing the drive shaft at the end of its cycle, and a return spring associated with the magnetic clutch for resetting the drive shaft back to its original or starting position.

The above and other features of novelty which characterize the invention are pointed out with particularity assembly in accordance with the invention;

Figure 2 is a top plan view of the presettable switching and control assembly shown in Figure 1;

Figure 3 is a side elevational view, in cross-section, of the limit switch and indexing wheel locking structure taken substantially as shown along line 3--3 of Figure 2;

Figure 4 is a side elevational view, in cross-section, of the cm wheel, rotor and switch structure taken substantially as shown along line 4-4 of Figure 2;

Figure 5 is a cross-sectional view of an illustrative presettable timing element taken substantially as shown along line 5-5 of Figure 4; and

Figure 6 is a perspective view of an illustrative embodiment of cam wheel in accordance with the invention.

Referring now to the drawing and more particularly to Figures 1 and 2 thereof, there is shown an illustrative embodiment of the invention which comprises a base it) having a front panel 12 and a constant speed drive source 14 supported thereon. Advantageously, drive source 14 may take the form of a constant speed motor and gear box assembly having an output adapted to be coupled by means of an electromagnetic clutch 16, as described in greater detail below, to an elongated drive shaft 18 positioned rearwardly of the front panel 12 and extending substantially the length thereof.

A plurality of presettable timing elements are operatively associated with drive shaft 18 to the end that circuit actuating switches coupled to the timing elements may be operated in a desired sequence and at desired times in accordance with the various settings of the timing elements.

As shown in greater detail in Figures 3 through 6, each presettable timing element comprises an indexing or calibration wheel 2% having a flange '22 at one end thereof, which advantageously is knurled around its periphery. The circumferential edge portion of indexing wheel 20 adjacent flange 22 is provided with a calibrated time scale, asshown in Figure 1, which advantageously may correspond to the cycle or time period of the drive shaft.

A cam wheel 26 is associated with indexing wheel 20 by any suitable means, such as a telescoping bushing arrangement. In one advantageous embodiment, as shown in Figure 5, a male bushing 28 is staked to the central aperture of the cam wheel 26 and a female bushing 39 is staked to the central aperture of the indexing wheel '20; In this manner, the indexing wheel 20 and the cam wheel 26 are axially movable relative to each other on drive shaft '18, and in accordance with one embodiment of the invention, suitable spring means, such as leaf springs 32, are provided between the indexing and cam wheels such that the cam wheel 26 normally is spring loaded away from the indexing wheel 20 on the drive shaft. It will be understood by those skilled in the art that other resilient biasing means may be used between the cam and indexing wheels, as for example, a plurality of spaced coil springs.

The bushing 30 of indexing wheel 20 is secured to. support bracket 34-, which in turn is mounted on the base 10, and the indexing wheel 20 is free to rotate on its bushing around drive shaft 18 when its knurled edge 22 is rotated. Cam wheel 26 advantageously is coupled to indexing wheel 2%),- as by means of the studs '36 secured to the cam wheel-and extending into suitable bushings '38 provided in the indexing wheel 20. Thus, as the indexing wheel 20 is rotated to a desired setting, the cam wheel 26fis rotatedinacorresponding manner. Itwill be appreciated at this point that this assembly permits relative motion between indexing Wheel 20 and cam wheel 26 along the axis of drive shaft 18, but when the indexing wheel is rotated around drive shaft 18, the cam wheel 26 follows.

A rotor assembly 40 comprising a hub 42 having a pair of oppositely disposed arms 44 and 46 of different lengths extending therefrom is positioned on drive shaft 18 and is secured thereto, as by means of set screw 48. The longer arm 44 of the rotor is provided with a'roller 50 at one end thereof which is adapted to ride in a cammed V raceway 52 recessed into one surfaceof the cam wheel 26. The shorter rotor arm 46 is provided with a roller 54 at one endthereof which is adapted to ride in a cammed raceway 56 recessed into theface of the cam wheel 26 and circumferentially spaced from cammed raceway 52.

The cammed raceways 52 and 56 in the cam wheel 26 are shown in greaterdetail in Figure v6 of the drawing. It can there be seen that raceway 52 is cut around 180 of a specific radius of the cam face and thateach end of this 180 arc tapers up to the cam face. Similarly, cammed raceway 56 is cut around 180 of a smaller radius of the cam face and that each end ofthis 180 are also tapers up to the cam face.

.It will be noted that the two cammed raceways 52 and 56 are oppositely positioned on thecam face such that raceway 52 is cut into one 180 portion of the cam face while the other raceway 56 is cut into the remaining 180 portionof the cam face. J

In the operation of the presettable timing element, the rotation of rotor 40 by the drive shaft 18 causes the cam wheel 26 to be moved toward and away from the indexing wheel 20 at a time in the cycle determined by the setting of the indexing wheel. It will be appreciated that sincethe cam wheel 26 is spring loaded away from the indexing wheel 20, as by means of the leaf springs 32, the rotor 40 serves to limit the distance of travel of the cam wheel 26 along the axis of drive shaft 18. It can be seen that the extent of this axial movement is determined by the depth of the raceways 52 and 56 cut into the face of cam wheel 26.

Thus, if the rollers 50 and 54 of the rotor 40 are riding in'their respective raceways in the cam wheel 26, the cam wheel is urged by the leaf springs 32 into its outermost position with respect to the indexing Wheel 20. As the rotor is driven around the raceways by the drive shaft 18, the rollers eventually ride on the tapered portions of the raceways, and at this time the cam wheel 26 is moved toward the indexing wheel against the bias of the leaf spring 32. Consequently, it can be seen that the rotation ofthe rotor 40 by the drive shaft 18 results in a movement of the cam Wheel 26 toward and away from the indexing wheel 20 at intervals dependent upon the position of the rollers 50 and 54 in their respective raceways.

For each individual presettable timing element the time in the cycle at which the cam wheel 26 ismoved toward or away from the indexing wheel 20 is determined by the initial setting of the indexing wheel .20 with respect to the'drive shaft 18. In accordance with an aspect of thisinvention, this initial setting is effected by means. of the knurled edge 22 of the indexing wheel which is made available through a Window 60 provided for each timing element inthe front panel 12 of the assembly. A pointer 6 2 is provided ateach window 60 to facilitate the setting of each indexing wheel to a desired position. Thus, the knurled edge 22 of an indexing wheel may be thumbed to any desired setting to enable movement of the cam Wheel 26 with respectto the indexing wheel 20 at a predetermined time in the drive shaft cycle.

In accordance with -a feature of the invention, this movement of the cam wheel 26 with respect to the indexing wheel 20 atthepredetermined time, of the drive shaft cycle is utilized to operate a circuit energizing switch associated with each presettable ,timing element. As shownin Figures 2, 4 and 5, a suitable circuit energizing 5 switch 64 is mounted on a bracket 66 secured to the front panel 12 above each timing element, and the armature 68 of each switch is provided with a roller 70 at its end which is adapted to ride on the cam face of its timing element. Thus, when the cam 26 is in its outermost position relative to the indexing wheel 20, the armature 68 of switch 64 is actuated to one of its operating positions and when the cam wheel 26 is moved inwardly toward the indexing wheel 20, the armature 68 follows to actuate switch 64 to its other operating condition. The terminals of each circuit energizing switch 24 advantageously are connected to the terminals of a barrier-type terminal strip 70 secured to the bracket 66 to the end that suitable load devices may be connected thereto for simultaneous or sequential energization in accordance with the settings of the various timing elements. It is an important aspect of this invention that the unique design of the cam wheel 26 and its cooperating rotor 40 enables the switch actuation to be maintained from the preset interval of actuation to the end of the cycle of operation. This is a distinct advantage for many applications wherein a momentary switch actuation would not be satisfactory.

The various timing'elements of this invention may be individually set to desired predetermined settings by means of a. reset press bar 72 extending forwardly of the front panel 12. Reset press bar 72 is supported by a pair of reset rods 74 which extend rearwardly of front panel 12 and which terminate in a reset bar 76 positioned at the rear portion of the assembly. Each reset rod 74 is provided with a coil spring 78 operative to spring load the press bar 72 in its forwardmost position as limited by a stop member 75 on the reset rod.

A plurality of locking fingers 80, which advantageously may take the form of leaf spring detents, are secured to the reset bar 76, one for each timing element, such that the indexing wheel of each timing element is locked into position by the engagement of one of the locking fingers with the indentations of the knurled portion of the indexing wheel. When it is desired to change the settings deny or all of the timing elements, the press bar 72 is pressed inwardly against the bias of the springs 78 to disengage the various locking fingers 80 from their associated indexing wheels. This releases the indexing wheels for rotation to any desired position and the release of press bar 72 locks the indexing wheels in their new po sitions.

Thus, it will be appreciated that each of the timing elements may be preset to individual settings for providing a timing function at the circuit energizing switches in any selected sequence. It will further be appreciated that once the indexing wheels are set this setting is maintained for as many cycles of operation as desired, and that this sequence may be changed in a simple and expedient fashion by merely pressing in press bar 72 and rotating the knurled portion of the indexing wheels to effect a diiferent sequence.

In one preferable embodiment of the invention, a pair of limit switches 82 and 84 are provided adjacent the presettable timing elements. As shown in Figure 3 of the drawing, each limit switch assembly comprises a cam 86 mounted on drive shaft 18 and operatively associated with a follower 88 positioned at the end of armature 91 of the limit switch. It will be understood by those skilled in the art that the cams 86 may be selected ,to provide signals at the beginning and at the end of the drive shaft cycle.

In accordance with one embodiment of this invention, the drive shaft 18 is coupled to the drive motor 14 by means of an electromagnetic clutch 16, as shown in Figure 1. Thus, when motor 14 is energized, the electromagnetic clutch operates to couple the output of the motor tothe drive shaft 18 for rotating the latter at the speed of the drive motor output. Advantageously, scroll spring 90 is secured at one end thereof to the output shaft 18 and the other end thereof to the motor housing 92. Thus, as the drive shaft is rotated by the drive mo tor, the scroll spring is loaded at the end of the drive shaft cycle. The de-energization of the drive motor 14 by the limit switch 84 at the end of the drive shaft cycle releases the electromagnetic clutch 16, and the loaded scroll spring unwinds to return the drive shaft to its initial or starting position. In this manner, the presettable timing assembly is reset at the end of each operating cycle. It will be appreciated by those skilled in the art that in lieu of the scroll spring arrangement for resetting the drive shaft, the latter may be reset to its original starting position by reversing the driving motor without releasing the clutch 16.

In one typical example of the example of the operation of the instant invention it can be assumed that the drive shaft has an operating cycle range of a selected number of hours and that 10 individual presettable timing elements are provided. Each timing element controls a circuit energizing switch which, in turn, controls a desired work circuit. The press bar 72 is pressed inwardly at each of the 10 timing elements to set up the desired sequence of operation. After the press bar is released and the drive motors is energized, the rotation of drive shaft 18 causes each timing element to actuate its associated circuit energizing switch at a desired preset time and in the desired sequence. At the end of the drive shaft cycle, the clutch spring return arrangement provides an automatic return to the starting position. It will be appreciated that by changing the speed of the driving motor and by changing the corresponding calibration of the indexing wheels, any desired time range can be incorporated in the invention.

Thus, we have shown and described a novel presettable automatic timing device in which one or more circuits may be sequenced and in which the switching function of each circuit is maintained from the selected time to the end of the cycle of the driving member. Further, the invention is provided with an automatic reset back to the starting position at the end of the cycle with all of the preselected time settings remaining in their original positions.

It will be understood by those skilled in the art that modifications may be made in the construction and arrangement of the parts of the above-described presettable automatic timing device without departing from the real spirit and purpose of the invention and that it is intended to cover by the appended claims any modified forms of structures, circuits or use of equivalents which may reasonably be used within their scope.

What is claimed as the invention is:

1. A presettable timing and control assembly comprising a constant speed drive shaft, a plurality of individually settable timing elements operatively associated with said drive shaft and adapted to be operated thereby for actuating circuit energizing switches at desired intervals in the cycle of operation of said drive shaft, each of said timing elements comprising an indexing wheel rotatably mounted around said drive shaft, a cam wheel rotatably mounted on said shaft and coupled to said indexing wheel for rotation therewith, said cam wheel being axially movable relative to said indexing wheel, a cammed raceway in the face of said cam wheel, rotor means secured to said drive shaft including a follower adapted to ride in said cammed raceway for causing said cam wheel to be moved towards and away from said index wheel in response to the rotation of said shaft at selected times dependent upon the setting of said indexing wheel, and a circuit energizing switch having an armature operatively associated with said cam wheel for actuating the switch to one position when the cam wheel is axially moved away from the index wheel and for actuating the switch to its other position when the cam wheel is axially moved towards the cam wheel.

7 2. A presettable timing and control assembly in accordancewith claim 1 further comprising retaining means for locking the indexing wheel in a preset position, and release means resiliently coupled to said retaining means for unlocking the indexing wheel when a different setting .is desired.

'3. A presettable timing and control assembly in accordance with claim 2 wherein said indexing wheel is provided with a plurality of indentations around its circum- :ference, and said retaining means comprises a leaf spring detent normally positioned in locking engagement with said indentations.

4. A presettable timing and control assembly comprising a driven shaft, a plurality of individually settable timing elements operatively associated with said drive shaft and adapted to be operated thereby for actuating circuit energizing switches at desired intervals in the cycle of operationof said driven shaft, each of said timing ele -ments comprising an index wheel .rotatably mounted .around said drive shaft, a cam wheel rotatably mounted on said shaft and coupled to said index wheel for rotation therewith around said shaft, said cam wheel being axially movable relative to said index wheel, means opandfor actuating the switch to its other position when .the cam wheel is axially moved towards the cam wheel,

retaining means for locking the index wheel in a preset position and manually operable release means resiliently coupled to said retaining means for unlocking the index wheel when adifferent setting is desired.

5. A presettable timing and control assembly compris- :ing.a.drive motor, a drive shaft, electrically energizable clutch means for coupling and decoupling said drive shaft to said motor, a plurality of individually settable timing elements operatively associated with said drive shaft, each of said timing elements comprising an indexing wheel rotatably mounted around said drive shaft, a cam wheel rotatably mounted on said shaft and coupled to saidindexing wheel for rotation therewith around said shaft, said cam wheel being axially movable relative to said indexing wheel,- a cammed raceway in the face of said cam wheel, rotor means secured to said drive shaft including a follower adapted. to ride in said cammed raceway for causing said cam wheel to be moved towards and away from said indexing wheel in response to the rotation of said shaft at selected times dependent upon the setting of said indexing wheel, a circuit energizing switch having an armature operatively associated with said cam wheel for actuating the switch to one position when the cam wheel is axially moved away from the index wheel and for actuating the switch to its other position when the cam Wheel is axially moved towards the cam wheel, retaining meansfor locking the index wheel in a preset position, manually operable release means resiliently coupled to said retaining means for unlocking the index wheel when a different setting is desired, limit switch means coupled to said drive shaft for de-energizing the drive motor when the latter completes its cycle, and reset means for said drive shaft coupled to said clutch means and operative upon de-energization of said motor for resetting said drive shaft to its starting position at the end of the motor cycle.

6. A presettable timing and control assembly comprising a driven shaft, a plurality of individually settable timing elements operatively associated with said driven shaft and adapted to be operated thereby, each of said timing elements comprising an index wheel rotatably mounted around said driven shaft, a cam wheel rotatably mounted v onsaid shaft and.coupled.to said index wheel for rotat ion therewith around said shaft, said camlwheel being axially movablerelativeto said index wheel, at least one cammed raceway intheface of said cam wheel and rotor means secured; to said driveshaft including a follower adapted to ride in said cammed raceway for causing said cam wheelto be, moved towards and away from said index wheel at selected times dependent upon the setting of said index wheel,-the movement of said cam wheel serving to providetiming signals at said selected times in the cycle of operation of said driven shaft.

7. A presettable timing and controlassembly in accordance with c l aim 6 wherein said cammed raceway describes a arc; about afirst radius of said cam wheel.

,8. A presettable timing and control assembly in accordance withclaim 7 wherein said cam wheel includes a second cammed raceway in the face thereof, said second cammed raceway describing a 180 are about a second radius of said cam wheel, different from said first radius.

9. In a presettabletiming and control assembly, the improvement of an individually settable timing element associated with a drive shaft and adapted to be operated thereby for actuating ircuit energizing switches at desired intervals, saidtim ing element comprising an index wheel rotatably mounted, around said drive shaft, a cam wheel rotatably mounted on said shaft and coupled to said index wheelfor rotation therewith around said shaft, said cam wheel being axially movable relative to said index wheel, at ,least one cammed raceway recessed in the face of said. cam wheel and describing a 180 ,arc around a radius thereof, androtor means secured to said drive shaft including a follower adapted to ride in said cammed raceway ,for causing said cam wheel to be moved towards and away from zsaid index wheel at selected times dependent upon the setting of said index wheel.

,10. The ,improvementpf an individually settable timing element in accordance with claim 9 wherein said cam wheel has a secondcammed raceway recessed in the face thereof and describing a 180 are around a radius differentfrom the radius of said first cammed raceway and I displaced 186? therefrom.

11., Ina presettabletiming and control assembly, the improvement of an individually settable timing element associatedwith a;drive shaft and adapted to, be operated thereby foractuating circuit energizing switches at desired intervals, said timing element comprising anindex wheel rotatablymounted aroundsaid drive shaft, a cam wheel rotatably. mounted on saidshaft and coupled to said index wheelfor rotation therewith around said shaft, said camwheel being-axiallymovable relative to saidindex wheel, acammed raceway recessed in the face of said cam wheel, and describing a 180? are around a radius thereof, rotor means securedto said drive'shaft including a fol lower adapted to rideinsaid' cammed raceway forcausing said camwheel tobe moved towards and away from said index wheel at selected times determined by the settingof said index wheel .and circuitfenergizing switch '.means having .an..armature. operatively associated with said camwheel. for actuating the switch to one position when .the cam wheel is axially moved away from the index wheel and for actuating the switch to its'other posi- Woodr'ow June 19, 1917 1,392,160 Hipple Sept. 27, 1921 1,866,422 -Ralph July 5, 1932 2,758,181 Crouch Aug. 7, 1956 2,803,715 .Guth Augf20, 1957 2,846,892

.Roessler .Aug. 12, 1958 

